Each year, over 19 million Americans smokers stop smoking for more than one day in an attempt to quit smoking, yet as few as 5% will maintain abstinence for one year, with most returning to smoking within one month of quitting. Relapse after smoking cessation is an important health concern and is the most significant problem faced by individuals who are attempting to maintain abstinence from smoking. The purpose of this study is to test the efficacy of IVR technology for enhancing a widely used tobacco treatment service delivery model (Free & Clear's Quit for Life(R) program) to prevent smoking relapse and achieve abstinence. Our technology will enhance quitline services through (1) screening individuals during the post quit date period for increased risk of relapse and (2) providing evidence-based telephone counseling at the point of need tailored to the individual's extant risk factors. Using IVR monitoring, individuals will be screened for specific indicators of increased risk for relapse including smoking lapse, physical withdrawal symptoms, depressive symptoms, perceived stress, decreased self-efficacy for quitting, and decreased motivation to quit. In addition to these well-established predictors of relapse, there is compelling evidence to suggest that the risk of relapse is most intense during the first two weeks post-quit. Thus we propose to compare two models for timing and frequency of IVR screening. In the Technology Enhanced Quitline (TEQ) arm, 10 proactive IVR calls will be placed at decreasing frequency for 8 weeks post-quit (twice a week for the first two weeks, then weekly). In the High Intensity Technology-Enhanced Quitline (HI-TEQ) arm, 20 proactive IVR calls will be placed over the 8 weeks post-quit (daily for the first 2 weeks, then weekly). The proposed study is a randomized controlled trial to compare smoking abstinence and cost-effectiveness at 6 and 12 months among participants in the Quit for Life quitline program. Three treatment groups will be compared, namely (1) standard Quit for Life care, (2) IVR monitoring of risk for smoking relapse in combination with telephone-based tobacco cessation treatment service (TEQ), and (3) high frequency monitoring of risk for smoking relapse in combination with telephone- based tobacco cessation treatment service (HI-TEQ). Subjects will be recruited from three large clients (two employers and one health plan client) of the Free & Clear Quit for Life telephone-based tobacco cessation treatment program. If successful, this intervention could be incorporated into existing quitline protocols and delivered to millions of individuals who are trying to quit smoking, meeting a significant public health need for the dissemination of effective smoking cessation interventions. Public Health Relevance: Relapse after smoking cessation is an important health concern and is the most significant problem faced by individuals who are attempting to maintain abstinence from smoking. The purpose of this study is to test the efficacy of IVR technology for enhancing telephone-based smoking cessation services to prevent smoking relapse and achieve abstinence and we will test two levels of an intervention to monitor relapse risk after an initial quit attempt by integrating IVR technology into a widely used existing service delivery model. If successful, this intervention could be incorporated into existing quitline protocols and delivered to millions of individuals who are trying to quit smoking, meeting a significant public health need for the dissemination of effective smoking cessation interventions.